linux/drivers/acpi/acpi_video.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  video.c - ACPI Video Driver
   4 *
   5 *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
   6 *  Copyright (C) 2004 Bruno Ducrot <ducrot@poupinou.org>
   7 *  Copyright (C) 2006 Thomas Tuttle <linux-kernel@ttuttle.net>
   8 */
   9
  10#define pr_fmt(fmt) "ACPI: video: " fmt
  11
  12#include <linux/kernel.h>
  13#include <linux/module.h>
  14#include <linux/init.h>
  15#include <linux/types.h>
  16#include <linux/list.h>
  17#include <linux/mutex.h>
  18#include <linux/input.h>
  19#include <linux/backlight.h>
  20#include <linux/thermal.h>
  21#include <linux/sort.h>
  22#include <linux/pci.h>
  23#include <linux/pci_ids.h>
  24#include <linux/slab.h>
  25#include <linux/dmi.h>
  26#include <linux/suspend.h>
  27#include <linux/acpi.h>
  28#include <acpi/video.h>
  29#include <linux/uaccess.h>
  30
  31#define ACPI_VIDEO_BUS_NAME             "Video Bus"
  32#define ACPI_VIDEO_DEVICE_NAME          "Video Device"
  33
  34#define MAX_NAME_LEN    20
  35
  36MODULE_AUTHOR("Bruno Ducrot");
  37MODULE_DESCRIPTION("ACPI Video Driver");
  38MODULE_LICENSE("GPL");
  39
  40static bool brightness_switch_enabled = true;
  41module_param(brightness_switch_enabled, bool, 0644);
  42
  43/*
  44 * By default, we don't allow duplicate ACPI video bus devices
  45 * under the same VGA controller
  46 */
  47static bool allow_duplicates;
  48module_param(allow_duplicates, bool, 0644);
  49
  50static int disable_backlight_sysfs_if = -1;
  51module_param(disable_backlight_sysfs_if, int, 0444);
  52
  53#define REPORT_OUTPUT_KEY_EVENTS                0x01
  54#define REPORT_BRIGHTNESS_KEY_EVENTS            0x02
  55static int report_key_events = -1;
  56module_param(report_key_events, int, 0644);
  57MODULE_PARM_DESC(report_key_events,
  58        "0: none, 1: output changes, 2: brightness changes, 3: all");
  59
  60static int hw_changes_brightness = -1;
  61module_param(hw_changes_brightness, int, 0644);
  62MODULE_PARM_DESC(hw_changes_brightness,
  63        "Set this to 1 on buggy hw which changes the brightness itself when "
  64        "a hotkey is pressed: -1: auto, 0: normal 1: hw-changes-brightness");
  65
  66/*
  67 * Whether the struct acpi_video_device_attrib::device_id_scheme bit should be
  68 * assumed even if not actually set.
  69 */
  70static bool device_id_scheme = false;
  71module_param(device_id_scheme, bool, 0444);
  72
  73static int only_lcd = -1;
  74module_param(only_lcd, int, 0444);
  75
  76static int register_count;
  77static DEFINE_MUTEX(register_count_mutex);
  78static DEFINE_MUTEX(video_list_lock);
  79static LIST_HEAD(video_bus_head);
  80static int acpi_video_bus_add(struct acpi_device *device);
  81static int acpi_video_bus_remove(struct acpi_device *device);
  82static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
  83void acpi_video_detect_exit(void);
  84
  85/*
  86 * Indices in the _BCL method response: the first two items are special,
  87 * the rest are all supported levels.
  88 *
  89 * See page 575 of the ACPI spec 3.0
  90 */
  91enum acpi_video_level_idx {
  92        ACPI_VIDEO_AC_LEVEL,            /* level when machine has full power */
  93        ACPI_VIDEO_BATTERY_LEVEL,       /* level when machine is on batteries */
  94        ACPI_VIDEO_FIRST_LEVEL,         /* actual supported levels begin here */
  95};
  96
  97static const struct acpi_device_id video_device_ids[] = {
  98        {ACPI_VIDEO_HID, 0},
  99        {"", 0},
 100};
 101MODULE_DEVICE_TABLE(acpi, video_device_ids);
 102
 103static struct acpi_driver acpi_video_bus = {
 104        .name = "video",
 105        .class = ACPI_VIDEO_CLASS,
 106        .ids = video_device_ids,
 107        .ops = {
 108                .add = acpi_video_bus_add,
 109                .remove = acpi_video_bus_remove,
 110                .notify = acpi_video_bus_notify,
 111                },
 112};
 113
 114struct acpi_video_bus_flags {
 115        u8 multihead:1;         /* can switch video heads */
 116        u8 rom:1;               /* can retrieve a video rom */
 117        u8 post:1;              /* can configure the head to */
 118        u8 reserved:5;
 119};
 120
 121struct acpi_video_bus_cap {
 122        u8 _DOS:1;              /* Enable/Disable output switching */
 123        u8 _DOD:1;              /* Enumerate all devices attached to display adapter */
 124        u8 _ROM:1;              /* Get ROM Data */
 125        u8 _GPD:1;              /* Get POST Device */
 126        u8 _SPD:1;              /* Set POST Device */
 127        u8 _VPO:1;              /* Video POST Options */
 128        u8 reserved:2;
 129};
 130
 131struct acpi_video_device_attrib {
 132        u32 display_index:4;    /* A zero-based instance of the Display */
 133        u32 display_port_attachment:4;  /* This field differentiates the display type */
 134        u32 display_type:4;     /* Describe the specific type in use */
 135        u32 vendor_specific:4;  /* Chipset Vendor Specific */
 136        u32 bios_can_detect:1;  /* BIOS can detect the device */
 137        u32 depend_on_vga:1;    /* Non-VGA output device whose power is related to
 138                                   the VGA device. */
 139        u32 pipe_id:3;          /* For VGA multiple-head devices. */
 140        u32 reserved:10;        /* Must be 0 */
 141
 142        /*
 143         * The device ID might not actually follow the scheme described by this
 144         * struct acpi_video_device_attrib. If it does, then this bit
 145         * device_id_scheme is set; otherwise, other fields should be ignored.
 146         *
 147         * (but also see the global flag device_id_scheme)
 148         */
 149        u32 device_id_scheme:1;
 150};
 151
 152struct acpi_video_enumerated_device {
 153        union {
 154                u32 int_val;
 155                struct acpi_video_device_attrib attrib;
 156        } value;
 157        struct acpi_video_device *bind_info;
 158};
 159
 160struct acpi_video_bus {
 161        struct acpi_device *device;
 162        bool backlight_registered;
 163        u8 dos_setting;
 164        struct acpi_video_enumerated_device *attached_array;
 165        u8 attached_count;
 166        u8 child_count;
 167        struct acpi_video_bus_cap cap;
 168        struct acpi_video_bus_flags flags;
 169        struct list_head video_device_list;
 170        struct mutex device_list_lock;  /* protects video_device_list */
 171        struct list_head entry;
 172        struct input_dev *input;
 173        char phys[32];  /* for input device */
 174        struct notifier_block pm_nb;
 175};
 176
 177struct acpi_video_device_flags {
 178        u8 crt:1;
 179        u8 lcd:1;
 180        u8 tvout:1;
 181        u8 dvi:1;
 182        u8 bios:1;
 183        u8 unknown:1;
 184        u8 notify:1;
 185        u8 reserved:1;
 186};
 187
 188struct acpi_video_device_cap {
 189        u8 _ADR:1;              /* Return the unique ID */
 190        u8 _BCL:1;              /* Query list of brightness control levels supported */
 191        u8 _BCM:1;              /* Set the brightness level */
 192        u8 _BQC:1;              /* Get current brightness level */
 193        u8 _BCQ:1;              /* Some buggy BIOS uses _BCQ instead of _BQC */
 194        u8 _DDC:1;              /* Return the EDID for this device */
 195};
 196
 197struct acpi_video_device {
 198        unsigned long device_id;
 199        struct acpi_video_device_flags flags;
 200        struct acpi_video_device_cap cap;
 201        struct list_head entry;
 202        struct delayed_work switch_brightness_work;
 203        int switch_brightness_event;
 204        struct acpi_video_bus *video;
 205        struct acpi_device *dev;
 206        struct acpi_video_device_brightness *brightness;
 207        struct backlight_device *backlight;
 208        struct thermal_cooling_device *cooling_dev;
 209};
 210
 211static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
 212static void acpi_video_device_rebind(struct acpi_video_bus *video);
 213static void acpi_video_device_bind(struct acpi_video_bus *video,
 214                                   struct acpi_video_device *device);
 215static int acpi_video_device_enumerate(struct acpi_video_bus *video);
 216static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
 217                        int level);
 218static int acpi_video_device_lcd_get_level_current(
 219                        struct acpi_video_device *device,
 220                        unsigned long long *level, bool raw);
 221static int acpi_video_get_next_level(struct acpi_video_device *device,
 222                                     u32 level_current, u32 event);
 223static void acpi_video_switch_brightness(struct work_struct *work);
 224
 225/* backlight device sysfs support */
 226static int acpi_video_get_brightness(struct backlight_device *bd)
 227{
 228        unsigned long long cur_level;
 229        int i;
 230        struct acpi_video_device *vd = bl_get_data(bd);
 231
 232        if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
 233                return -EINVAL;
 234        for (i = ACPI_VIDEO_FIRST_LEVEL; i < vd->brightness->count; i++) {
 235                if (vd->brightness->levels[i] == cur_level)
 236                        return i - ACPI_VIDEO_FIRST_LEVEL;
 237        }
 238        return 0;
 239}
 240
 241static int acpi_video_set_brightness(struct backlight_device *bd)
 242{
 243        int request_level = bd->props.brightness + ACPI_VIDEO_FIRST_LEVEL;
 244        struct acpi_video_device *vd = bl_get_data(bd);
 245
 246        cancel_delayed_work(&vd->switch_brightness_work);
 247        return acpi_video_device_lcd_set_level(vd,
 248                                vd->brightness->levels[request_level]);
 249}
 250
 251static const struct backlight_ops acpi_backlight_ops = {
 252        .get_brightness = acpi_video_get_brightness,
 253        .update_status  = acpi_video_set_brightness,
 254};
 255
 256/* thermal cooling device callbacks */
 257static int video_get_max_state(struct thermal_cooling_device *cooling_dev,
 258                               unsigned long *state)
 259{
 260        struct acpi_device *device = cooling_dev->devdata;
 261        struct acpi_video_device *video = acpi_driver_data(device);
 262
 263        *state = video->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
 264        return 0;
 265}
 266
 267static int video_get_cur_state(struct thermal_cooling_device *cooling_dev,
 268                               unsigned long *state)
 269{
 270        struct acpi_device *device = cooling_dev->devdata;
 271        struct acpi_video_device *video = acpi_driver_data(device);
 272        unsigned long long level;
 273        int offset;
 274
 275        if (acpi_video_device_lcd_get_level_current(video, &level, false))
 276                return -EINVAL;
 277        for (offset = ACPI_VIDEO_FIRST_LEVEL; offset < video->brightness->count;
 278             offset++)
 279                if (level == video->brightness->levels[offset]) {
 280                        *state = video->brightness->count - offset - 1;
 281                        return 0;
 282                }
 283
 284        return -EINVAL;
 285}
 286
 287static int
 288video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
 289{
 290        struct acpi_device *device = cooling_dev->devdata;
 291        struct acpi_video_device *video = acpi_driver_data(device);
 292        int level;
 293
 294        if (state >= video->brightness->count - ACPI_VIDEO_FIRST_LEVEL)
 295                return -EINVAL;
 296
 297        state = video->brightness->count - state;
 298        level = video->brightness->levels[state - 1];
 299        return acpi_video_device_lcd_set_level(video, level);
 300}
 301
 302static const struct thermal_cooling_device_ops video_cooling_ops = {
 303        .get_max_state = video_get_max_state,
 304        .get_cur_state = video_get_cur_state,
 305        .set_cur_state = video_set_cur_state,
 306};
 307
 308/*
 309 * --------------------------------------------------------------------------
 310 *                             Video Management
 311 * --------------------------------------------------------------------------
 312 */
 313
 314static int
 315acpi_video_device_lcd_query_levels(acpi_handle handle,
 316                                   union acpi_object **levels)
 317{
 318        int status;
 319        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 320        union acpi_object *obj;
 321
 322
 323        *levels = NULL;
 324
 325        status = acpi_evaluate_object(handle, "_BCL", NULL, &buffer);
 326        if (ACPI_FAILURE(status))
 327                return status;
 328        obj = (union acpi_object *)buffer.pointer;
 329        if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
 330                acpi_handle_info(handle, "Invalid _BCL data\n");
 331                status = -EFAULT;
 332                goto err;
 333        }
 334
 335        *levels = obj;
 336
 337        return 0;
 338
 339err:
 340        kfree(buffer.pointer);
 341
 342        return status;
 343}
 344
 345static int
 346acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
 347{
 348        int status;
 349        int state;
 350
 351        status = acpi_execute_simple_method(device->dev->handle,
 352                                            "_BCM", level);
 353        if (ACPI_FAILURE(status)) {
 354                acpi_handle_info(device->dev->handle, "_BCM evaluation failed\n");
 355                return -EIO;
 356        }
 357
 358        device->brightness->curr = level;
 359        for (state = ACPI_VIDEO_FIRST_LEVEL; state < device->brightness->count;
 360             state++)
 361                if (level == device->brightness->levels[state]) {
 362                        if (device->backlight)
 363                                device->backlight->props.brightness =
 364                                        state - ACPI_VIDEO_FIRST_LEVEL;
 365                        return 0;
 366                }
 367
 368        acpi_handle_info(device->dev->handle, "Current brightness invalid\n");
 369        return -EINVAL;
 370}
 371
 372/*
 373 * For some buggy _BQC methods, we need to add a constant value to
 374 * the _BQC return value to get the actual current brightness level
 375 */
 376
 377static int bqc_offset_aml_bug_workaround;
 378static int video_set_bqc_offset(const struct dmi_system_id *d)
 379{
 380        bqc_offset_aml_bug_workaround = 9;
 381        return 0;
 382}
 383
 384static int video_disable_backlight_sysfs_if(
 385        const struct dmi_system_id *d)
 386{
 387        if (disable_backlight_sysfs_if == -1)
 388                disable_backlight_sysfs_if = 1;
 389        return 0;
 390}
 391
 392static int video_set_device_id_scheme(const struct dmi_system_id *d)
 393{
 394        device_id_scheme = true;
 395        return 0;
 396}
 397
 398static int video_enable_only_lcd(const struct dmi_system_id *d)
 399{
 400        only_lcd = true;
 401        return 0;
 402}
 403
 404static int video_set_report_key_events(const struct dmi_system_id *id)
 405{
 406        if (report_key_events == -1)
 407                report_key_events = (uintptr_t)id->driver_data;
 408        return 0;
 409}
 410
 411static int video_hw_changes_brightness(
 412        const struct dmi_system_id *d)
 413{
 414        if (hw_changes_brightness == -1)
 415                hw_changes_brightness = 1;
 416        return 0;
 417}
 418
 419static const struct dmi_system_id video_dmi_table[] = {
 420        /*
 421         * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
 422         */
 423        {
 424         .callback = video_set_bqc_offset,
 425         .ident = "Acer Aspire 5720",
 426         .matches = {
 427                DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 428                DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
 429                },
 430        },
 431        {
 432         .callback = video_set_bqc_offset,
 433         .ident = "Acer Aspire 5710Z",
 434         .matches = {
 435                DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 436                DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
 437                },
 438        },
 439        {
 440         .callback = video_set_bqc_offset,
 441         .ident = "eMachines E510",
 442         .matches = {
 443                DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
 444                DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
 445                },
 446        },
 447        {
 448         .callback = video_set_bqc_offset,
 449         .ident = "Acer Aspire 5315",
 450         .matches = {
 451                DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 452                DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
 453                },
 454        },
 455        {
 456         .callback = video_set_bqc_offset,
 457         .ident = "Acer Aspire 7720",
 458         .matches = {
 459                DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 460                DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
 461                },
 462        },
 463
 464        /*
 465         * Some machines have a broken acpi-video interface for brightness
 466         * control, but still need an acpi_video_device_lcd_set_level() call
 467         * on resume to turn the backlight power on.  We Enable backlight
 468         * control on these systems, but do not register a backlight sysfs
 469         * as brightness control does not work.
 470         */
 471        {
 472         /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
 473         .callback = video_disable_backlight_sysfs_if,
 474         .ident = "Toshiba Portege R700",
 475         .matches = {
 476                DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 477                DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R700"),
 478                },
 479        },
 480        {
 481         /* https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
 482         .callback = video_disable_backlight_sysfs_if,
 483         .ident = "Toshiba Portege R830",
 484         .matches = {
 485                DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 486                DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R830"),
 487                },
 488        },
 489        {
 490         /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
 491         .callback = video_disable_backlight_sysfs_if,
 492         .ident = "Toshiba Satellite R830",
 493         .matches = {
 494                DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 495                DMI_MATCH(DMI_PRODUCT_NAME, "SATELLITE R830"),
 496                },
 497        },
 498        /*
 499         * Some machine's _DOD IDs don't have bit 31(Device ID Scheme) set
 500         * but the IDs actually follow the Device ID Scheme.
 501         */
 502        {
 503         /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 504         .callback = video_set_device_id_scheme,
 505         .ident = "ESPRIMO Mobile M9410",
 506         .matches = {
 507                DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 508                DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 509                },
 510        },
 511        /*
 512         * Some machines have multiple video output devices, but only the one
 513         * that is the type of LCD can do the backlight control so we should not
 514         * register backlight interface for other video output devices.
 515         */
 516        {
 517         /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 518         .callback = video_enable_only_lcd,
 519         .ident = "ESPRIMO Mobile M9410",
 520         .matches = {
 521                DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 522                DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 523                },
 524        },
 525        /*
 526         * Some machines report wrong key events on the acpi-bus, suppress
 527         * key event reporting on these.  Note this is only intended to work
 528         * around events which are plain wrong. In some cases we get double
 529         * events, in this case acpi-video is considered the canonical source
 530         * and the events from the other source should be filtered. E.g.
 531         * by calling acpi_video_handles_brightness_key_presses() from the
 532         * vendor acpi/wmi driver or by using /lib/udev/hwdb.d/60-keyboard.hwdb
 533         */
 534        {
 535         .callback = video_set_report_key_events,
 536         .driver_data = (void *)((uintptr_t)REPORT_OUTPUT_KEY_EVENTS),
 537         .ident = "Dell Vostro V131",
 538         .matches = {
 539                DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 540                DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
 541                },
 542        },
 543        {
 544         .callback = video_set_report_key_events,
 545         .driver_data = (void *)((uintptr_t)REPORT_BRIGHTNESS_KEY_EVENTS),
 546         .ident = "Dell Vostro 3350",
 547         .matches = {
 548                DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 549                DMI_MATCH(DMI_PRODUCT_NAME, "Vostro 3350"),
 550                },
 551        },
 552        /*
 553         * Some machines change the brightness themselves when a brightness
 554         * hotkey gets pressed, despite us telling them not to. In this case
 555         * acpi_video_device_notify() should only call backlight_force_update(
 556         * BACKLIGHT_UPDATE_HOTKEY) and not do anything else.
 557         */
 558        {
 559         /* https://bugzilla.kernel.org/show_bug.cgi?id=204077 */
 560         .callback = video_hw_changes_brightness,
 561         .ident = "Packard Bell EasyNote MZ35",
 562         .matches = {
 563                DMI_MATCH(DMI_SYS_VENDOR, "Packard Bell"),
 564                DMI_MATCH(DMI_PRODUCT_NAME, "EasyNote MZ35"),
 565                },
 566        },
 567        {}
 568};
 569
 570static unsigned long long
 571acpi_video_bqc_value_to_level(struct acpi_video_device *device,
 572                              unsigned long long bqc_value)
 573{
 574        unsigned long long level;
 575
 576        if (device->brightness->flags._BQC_use_index) {
 577                /*
 578                 * _BQC returns an index that doesn't account for the first 2
 579                 * items with special meaning (see enum acpi_video_level_idx),
 580                 * so we need to compensate for that by offsetting ourselves
 581                 */
 582                if (device->brightness->flags._BCL_reversed)
 583                        bqc_value = device->brightness->count -
 584                                ACPI_VIDEO_FIRST_LEVEL - 1 - bqc_value;
 585
 586                level = device->brightness->levels[bqc_value +
 587                                                   ACPI_VIDEO_FIRST_LEVEL];
 588        } else {
 589                level = bqc_value;
 590        }
 591
 592        level += bqc_offset_aml_bug_workaround;
 593
 594        return level;
 595}
 596
 597static int
 598acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
 599                                        unsigned long long *level, bool raw)
 600{
 601        acpi_status status = AE_OK;
 602        int i;
 603
 604        if (device->cap._BQC || device->cap._BCQ) {
 605                char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
 606
 607                status = acpi_evaluate_integer(device->dev->handle, buf,
 608                                                NULL, level);
 609                if (ACPI_SUCCESS(status)) {
 610                        if (raw) {
 611                                /*
 612                                 * Caller has indicated he wants the raw
 613                                 * value returned by _BQC, so don't furtherly
 614                                 * mess with the value.
 615                                 */
 616                                return 0;
 617                        }
 618
 619                        *level = acpi_video_bqc_value_to_level(device, *level);
 620
 621                        for (i = ACPI_VIDEO_FIRST_LEVEL;
 622                             i < device->brightness->count; i++)
 623                                if (device->brightness->levels[i] == *level) {
 624                                        device->brightness->curr = *level;
 625                                        return 0;
 626                                }
 627                        /*
 628                         * BQC returned an invalid level.
 629                         * Stop using it.
 630                         */
 631                        acpi_handle_info(device->dev->handle,
 632                                         "%s returned an invalid level", buf);
 633                        device->cap._BQC = device->cap._BCQ = 0;
 634                } else {
 635                        /*
 636                         * Fixme:
 637                         * should we return an error or ignore this failure?
 638                         * dev->brightness->curr is a cached value which stores
 639                         * the correct current backlight level in most cases.
 640                         * ACPI video backlight still works w/ buggy _BQC.
 641                         * http://bugzilla.kernel.org/show_bug.cgi?id=12233
 642                         */
 643                        acpi_handle_info(device->dev->handle,
 644                                         "%s evaluation failed", buf);
 645                        device->cap._BQC = device->cap._BCQ = 0;
 646                }
 647        }
 648
 649        *level = device->brightness->curr;
 650        return 0;
 651}
 652
 653static int
 654acpi_video_device_EDID(struct acpi_video_device *device,
 655                       union acpi_object **edid, ssize_t length)
 656{
 657        int status;
 658        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 659        union acpi_object *obj;
 660        union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 661        struct acpi_object_list args = { 1, &arg0 };
 662
 663
 664        *edid = NULL;
 665
 666        if (!device)
 667                return -ENODEV;
 668        if (length == 128)
 669                arg0.integer.value = 1;
 670        else if (length == 256)
 671                arg0.integer.value = 2;
 672        else
 673                return -EINVAL;
 674
 675        status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
 676        if (ACPI_FAILURE(status))
 677                return -ENODEV;
 678
 679        obj = buffer.pointer;
 680
 681        if (obj && obj->type == ACPI_TYPE_BUFFER)
 682                *edid = obj;
 683        else {
 684                acpi_handle_info(device->dev->handle, "Invalid _DDC data\n");
 685                status = -EFAULT;
 686                kfree(obj);
 687        }
 688
 689        return status;
 690}
 691
 692/* bus */
 693
 694/*
 695 *  Arg:
 696 *      video           : video bus device pointer
 697 *      bios_flag       :
 698 *              0.      The system BIOS should NOT automatically switch(toggle)
 699 *                      the active display output.
 700 *              1.      The system BIOS should automatically switch (toggle) the
 701 *                      active display output. No switch event.
 702 *              2.      The _DGS value should be locked.
 703 *              3.      The system BIOS should not automatically switch (toggle) the
 704 *                      active display output, but instead generate the display switch
 705 *                      event notify code.
 706 *      lcd_flag        :
 707 *              0.      The system BIOS should automatically control the brightness level
 708 *                      of the LCD when:
 709 *                      - the power changes from AC to DC (ACPI appendix B)
 710 *                      - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
 711 *              1.      The system BIOS should NOT automatically control the brightness
 712 *                      level of the LCD when:
 713 *                      - the power changes from AC to DC (ACPI appendix B)
 714 *                      - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
 715 *  Return Value:
 716 *              -EINVAL wrong arg.
 717 */
 718
 719static int
 720acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 721{
 722        acpi_status status;
 723
 724        if (!video->cap._DOS)
 725                return 0;
 726
 727        if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
 728                return -EINVAL;
 729        video->dos_setting = (lcd_flag << 2) | bios_flag;
 730        status = acpi_execute_simple_method(video->device->handle, "_DOS",
 731                                            (lcd_flag << 2) | bios_flag);
 732        if (ACPI_FAILURE(status))
 733                return -EIO;
 734
 735        return 0;
 736}
 737
 738/*
 739 * Simple comparison function used to sort backlight levels.
 740 */
 741
 742static int
 743acpi_video_cmp_level(const void *a, const void *b)
 744{
 745        return *(int *)a - *(int *)b;
 746}
 747
 748/*
 749 * Decides if _BQC/_BCQ for this system is usable
 750 *
 751 * We do this by changing the level first and then read out the current
 752 * brightness level, if the value does not match, find out if it is using
 753 * index. If not, clear the _BQC/_BCQ capability.
 754 */
 755static int acpi_video_bqc_quirk(struct acpi_video_device *device,
 756                                int max_level, int current_level)
 757{
 758        struct acpi_video_device_brightness *br = device->brightness;
 759        int result;
 760        unsigned long long level;
 761        int test_level;
 762
 763        /* don't mess with existing known broken systems */
 764        if (bqc_offset_aml_bug_workaround)
 765                return 0;
 766
 767        /*
 768         * Some systems always report current brightness level as maximum
 769         * through _BQC, we need to test another value for them. However,
 770         * there is a subtlety:
 771         *
 772         * If the _BCL package ordering is descending, the first level
 773         * (br->levels[2]) is likely to be 0, and if the number of levels
 774         * matches the number of steps, we might confuse a returned level to
 775         * mean the index.
 776         *
 777         * For example:
 778         *
 779         *     current_level = max_level = 100
 780         *     test_level = 0
 781         *     returned level = 100
 782         *
 783         * In this case 100 means the level, not the index, and _BCM failed.
 784         * Still, if the _BCL package ordering is descending, the index of
 785         * level 0 is also 100, so we assume _BQC is indexed, when it's not.
 786         *
 787         * This causes all _BQC calls to return bogus values causing weird
 788         * behavior from the user's perspective.  For example:
 789         *
 790         * xbacklight -set 10; xbacklight -set 20;
 791         *
 792         * would flash to 90% and then slowly down to the desired level (20).
 793         *
 794         * The solution is simple; test anything other than the first level
 795         * (e.g. 1).
 796         */
 797        test_level = current_level == max_level
 798                ? br->levels[ACPI_VIDEO_FIRST_LEVEL + 1]
 799                : max_level;
 800
 801        result = acpi_video_device_lcd_set_level(device, test_level);
 802        if (result)
 803                return result;
 804
 805        result = acpi_video_device_lcd_get_level_current(device, &level, true);
 806        if (result)
 807                return result;
 808
 809        if (level != test_level) {
 810                /* buggy _BQC found, need to find out if it uses index */
 811                if (level < br->count) {
 812                        if (br->flags._BCL_reversed)
 813                                level = br->count - ACPI_VIDEO_FIRST_LEVEL - 1 - level;
 814                        if (br->levels[level + ACPI_VIDEO_FIRST_LEVEL] == test_level)
 815                                br->flags._BQC_use_index = 1;
 816                }
 817
 818                if (!br->flags._BQC_use_index)
 819                        device->cap._BQC = device->cap._BCQ = 0;
 820        }
 821
 822        return 0;
 823}
 824
 825int acpi_video_get_levels(struct acpi_device *device,
 826                          struct acpi_video_device_brightness **dev_br,
 827                          int *pmax_level)
 828{
 829        union acpi_object *obj = NULL;
 830        int i, max_level = 0, count = 0, level_ac_battery = 0;
 831        union acpi_object *o;
 832        struct acpi_video_device_brightness *br = NULL;
 833        int result = 0;
 834        u32 value;
 835
 836        if (ACPI_FAILURE(acpi_video_device_lcd_query_levels(device->handle, &obj))) {
 837                acpi_handle_debug(device->handle,
 838                                  "Could not query available LCD brightness level\n");
 839                result = -ENODEV;
 840                goto out;
 841        }
 842
 843        if (obj->package.count < ACPI_VIDEO_FIRST_LEVEL) {
 844                result = -EINVAL;
 845                goto out;
 846        }
 847
 848        br = kzalloc(sizeof(*br), GFP_KERNEL);
 849        if (!br) {
 850                result = -ENOMEM;
 851                goto out;
 852        }
 853
 854        /*
 855         * Note that we have to reserve 2 extra items (ACPI_VIDEO_FIRST_LEVEL),
 856         * in order to account for buggy BIOS which don't export the first two
 857         * special levels (see below)
 858         */
 859        br->levels = kmalloc_array(obj->package.count + ACPI_VIDEO_FIRST_LEVEL,
 860                                   sizeof(*br->levels),
 861                                   GFP_KERNEL);
 862        if (!br->levels) {
 863                result = -ENOMEM;
 864                goto out_free;
 865        }
 866
 867        for (i = 0; i < obj->package.count; i++) {
 868                o = (union acpi_object *)&obj->package.elements[i];
 869                if (o->type != ACPI_TYPE_INTEGER) {
 870                        acpi_handle_info(device->handle, "Invalid data\n");
 871                        continue;
 872                }
 873                value = (u32) o->integer.value;
 874                /* Skip duplicate entries */
 875                if (count > ACPI_VIDEO_FIRST_LEVEL
 876                    && br->levels[count - 1] == value)
 877                        continue;
 878
 879                br->levels[count] = value;
 880
 881                if (br->levels[count] > max_level)
 882                        max_level = br->levels[count];
 883                count++;
 884        }
 885
 886        /*
 887         * some buggy BIOS don't export the levels
 888         * when machine is on AC/Battery in _BCL package.
 889         * In this case, the first two elements in _BCL packages
 890         * are also supported brightness levels that OS should take care of.
 891         */
 892        for (i = ACPI_VIDEO_FIRST_LEVEL; i < count; i++) {
 893                if (br->levels[i] == br->levels[ACPI_VIDEO_AC_LEVEL])
 894                        level_ac_battery++;
 895                if (br->levels[i] == br->levels[ACPI_VIDEO_BATTERY_LEVEL])
 896                        level_ac_battery++;
 897        }
 898
 899        if (level_ac_battery < ACPI_VIDEO_FIRST_LEVEL) {
 900                level_ac_battery = ACPI_VIDEO_FIRST_LEVEL - level_ac_battery;
 901                br->flags._BCL_no_ac_battery_levels = 1;
 902                for (i = (count - 1 + level_ac_battery);
 903                     i >= ACPI_VIDEO_FIRST_LEVEL; i--)
 904                        br->levels[i] = br->levels[i - level_ac_battery];
 905                count += level_ac_battery;
 906        } else if (level_ac_battery > ACPI_VIDEO_FIRST_LEVEL)
 907                acpi_handle_info(device->handle,
 908                                 "Too many duplicates in _BCL package");
 909
 910        /* Check if the _BCL package is in a reversed order */
 911        if (max_level == br->levels[ACPI_VIDEO_FIRST_LEVEL]) {
 912                br->flags._BCL_reversed = 1;
 913                sort(&br->levels[ACPI_VIDEO_FIRST_LEVEL],
 914                     count - ACPI_VIDEO_FIRST_LEVEL,
 915                     sizeof(br->levels[ACPI_VIDEO_FIRST_LEVEL]),
 916                     acpi_video_cmp_level, NULL);
 917        } else if (max_level != br->levels[count - 1])
 918                acpi_handle_info(device->handle,
 919                                 "Found unordered _BCL package");
 920
 921        br->count = count;
 922        *dev_br = br;
 923        if (pmax_level)
 924                *pmax_level = max_level;
 925
 926out:
 927        kfree(obj);
 928        return result;
 929out_free:
 930        kfree(br);
 931        goto out;
 932}
 933EXPORT_SYMBOL(acpi_video_get_levels);
 934
 935/*
 936 *  Arg:
 937 *      device  : video output device (LCD, CRT, ..)
 938 *
 939 *  Return Value:
 940 *      Maximum brightness level
 941 *
 942 *  Allocate and initialize device->brightness.
 943 */
 944
 945static int
 946acpi_video_init_brightness(struct acpi_video_device *device)
 947{
 948        int i, max_level = 0;
 949        unsigned long long level, level_old;
 950        struct acpi_video_device_brightness *br = NULL;
 951        int result;
 952
 953        result = acpi_video_get_levels(device->dev, &br, &max_level);
 954        if (result)
 955                return result;
 956        device->brightness = br;
 957
 958        /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
 959        br->curr = level = max_level;
 960
 961        if (!device->cap._BQC)
 962                goto set_level;
 963
 964        result = acpi_video_device_lcd_get_level_current(device,
 965                                                         &level_old, true);
 966        if (result)
 967                goto out_free_levels;
 968
 969        result = acpi_video_bqc_quirk(device, max_level, level_old);
 970        if (result)
 971                goto out_free_levels;
 972        /*
 973         * cap._BQC may get cleared due to _BQC is found to be broken
 974         * in acpi_video_bqc_quirk, so check again here.
 975         */
 976        if (!device->cap._BQC)
 977                goto set_level;
 978
 979        level = acpi_video_bqc_value_to_level(device, level_old);
 980        /*
 981         * On some buggy laptops, _BQC returns an uninitialized
 982         * value when invoked for the first time, i.e.
 983         * level_old is invalid (no matter whether it's a level
 984         * or an index). Set the backlight to max_level in this case.
 985         */
 986        for (i = ACPI_VIDEO_FIRST_LEVEL; i < br->count; i++)
 987                if (level == br->levels[i])
 988                        break;
 989        if (i == br->count || !level)
 990                level = max_level;
 991
 992set_level:
 993        result = acpi_video_device_lcd_set_level(device, level);
 994        if (result)
 995                goto out_free_levels;
 996
 997        acpi_handle_debug(device->dev->handle, "found %d brightness levels\n",
 998                          br->count - ACPI_VIDEO_FIRST_LEVEL);
 999
1000        return 0;
1001
1002out_free_levels:
1003        kfree(br->levels);
1004        kfree(br);
1005        device->brightness = NULL;
1006        return result;
1007}
1008
1009/*
1010 *  Arg:
1011 *      device  : video output device (LCD, CRT, ..)
1012 *
1013 *  Return Value:
1014 *      None
1015 *
1016 *  Find out all required AML methods defined under the output
1017 *  device.
1018 */
1019
1020static void acpi_video_device_find_cap(struct acpi_video_device *device)
1021{
1022        if (acpi_has_method(device->dev->handle, "_ADR"))
1023                device->cap._ADR = 1;
1024        if (acpi_has_method(device->dev->handle, "_BCL"))
1025                device->cap._BCL = 1;
1026        if (acpi_has_method(device->dev->handle, "_BCM"))
1027                device->cap._BCM = 1;
1028        if (acpi_has_method(device->dev->handle, "_BQC")) {
1029                device->cap._BQC = 1;
1030        } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
1031                acpi_handle_info(device->dev->handle,
1032                                 "_BCQ is used instead of _BQC\n");
1033                device->cap._BCQ = 1;
1034        }
1035
1036        if (acpi_has_method(device->dev->handle, "_DDC"))
1037                device->cap._DDC = 1;
1038}
1039
1040/*
1041 *  Arg:
1042 *      device  : video output device (VGA)
1043 *
1044 *  Return Value:
1045 *      None
1046 *
1047 *  Find out all required AML methods defined under the video bus device.
1048 */
1049
1050static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
1051{
1052        if (acpi_has_method(video->device->handle, "_DOS"))
1053                video->cap._DOS = 1;
1054        if (acpi_has_method(video->device->handle, "_DOD"))
1055                video->cap._DOD = 1;
1056        if (acpi_has_method(video->device->handle, "_ROM"))
1057                video->cap._ROM = 1;
1058        if (acpi_has_method(video->device->handle, "_GPD"))
1059                video->cap._GPD = 1;
1060        if (acpi_has_method(video->device->handle, "_SPD"))
1061                video->cap._SPD = 1;
1062        if (acpi_has_method(video->device->handle, "_VPO"))
1063                video->cap._VPO = 1;
1064}
1065
1066/*
1067 * Check whether the video bus device has required AML method to
1068 * support the desired features
1069 */
1070
1071static int acpi_video_bus_check(struct acpi_video_bus *video)
1072{
1073        acpi_status status = -ENOENT;
1074        struct pci_dev *dev;
1075
1076        if (!video)
1077                return -EINVAL;
1078
1079        dev = acpi_get_pci_dev(video->device->handle);
1080        if (!dev)
1081                return -ENODEV;
1082        pci_dev_put(dev);
1083
1084        /*
1085         * Since there is no HID, CID and so on for VGA driver, we have
1086         * to check well known required nodes.
1087         */
1088
1089        /* Does this device support video switching? */
1090        if (video->cap._DOS || video->cap._DOD) {
1091                if (!video->cap._DOS) {
1092                        pr_info(FW_BUG "ACPI(%s) defines _DOD but not _DOS\n",
1093                                acpi_device_bid(video->device));
1094                }
1095                video->flags.multihead = 1;
1096                status = 0;
1097        }
1098
1099        /* Does this device support retrieving a video ROM? */
1100        if (video->cap._ROM) {
1101                video->flags.rom = 1;
1102                status = 0;
1103        }
1104
1105        /* Does this device support configuring which video device to POST? */
1106        if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1107                video->flags.post = 1;
1108                status = 0;
1109        }
1110
1111        return status;
1112}
1113
1114/*
1115 * --------------------------------------------------------------------------
1116 *                               Driver Interface
1117 * --------------------------------------------------------------------------
1118 */
1119
1120/* device interface */
1121static struct acpi_video_device_attrib *
1122acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1123{
1124        struct acpi_video_enumerated_device *ids;
1125        int i;
1126
1127        for (i = 0; i < video->attached_count; i++) {
1128                ids = &video->attached_array[i];
1129                if ((ids->value.int_val & 0xffff) == device_id)
1130                        return &ids->value.attrib;
1131        }
1132
1133        return NULL;
1134}
1135
1136static int
1137acpi_video_get_device_type(struct acpi_video_bus *video,
1138                           unsigned long device_id)
1139{
1140        struct acpi_video_enumerated_device *ids;
1141        int i;
1142
1143        for (i = 0; i < video->attached_count; i++) {
1144                ids = &video->attached_array[i];
1145                if ((ids->value.int_val & 0xffff) == device_id)
1146                        return ids->value.int_val;
1147        }
1148
1149        return 0;
1150}
1151
1152static int
1153acpi_video_bus_get_one_device(struct acpi_device *device,
1154                              struct acpi_video_bus *video)
1155{
1156        unsigned long long device_id;
1157        int status, device_type;
1158        struct acpi_video_device *data;
1159        struct acpi_video_device_attrib *attribute;
1160
1161        status =
1162            acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1163        /* Some device omits _ADR, we skip them instead of fail */
1164        if (ACPI_FAILURE(status))
1165                return 0;
1166
1167        data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1168        if (!data)
1169                return -ENOMEM;
1170
1171        strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1172        strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1173        device->driver_data = data;
1174
1175        data->device_id = device_id;
1176        data->video = video;
1177        data->dev = device;
1178        INIT_DELAYED_WORK(&data->switch_brightness_work,
1179                          acpi_video_switch_brightness);
1180
1181        attribute = acpi_video_get_device_attr(video, device_id);
1182
1183        if (attribute && (attribute->device_id_scheme || device_id_scheme)) {
1184                switch (attribute->display_type) {
1185                case ACPI_VIDEO_DISPLAY_CRT:
1186                        data->flags.crt = 1;
1187                        break;
1188                case ACPI_VIDEO_DISPLAY_TV:
1189                        data->flags.tvout = 1;
1190                        break;
1191                case ACPI_VIDEO_DISPLAY_DVI:
1192                        data->flags.dvi = 1;
1193                        break;
1194                case ACPI_VIDEO_DISPLAY_LCD:
1195                        data->flags.lcd = 1;
1196                        break;
1197                default:
1198                        data->flags.unknown = 1;
1199                        break;
1200                }
1201                if (attribute->bios_can_detect)
1202                        data->flags.bios = 1;
1203        } else {
1204                /* Check for legacy IDs */
1205                device_type = acpi_video_get_device_type(video, device_id);
1206                /* Ignore bits 16 and 18-20 */
1207                switch (device_type & 0xffe2ffff) {
1208                case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1209                        data->flags.crt = 1;
1210                        break;
1211                case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1212                        data->flags.lcd = 1;
1213                        break;
1214                case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1215                        data->flags.tvout = 1;
1216                        break;
1217                default:
1218                        data->flags.unknown = 1;
1219                }
1220        }
1221
1222        acpi_video_device_bind(video, data);
1223        acpi_video_device_find_cap(data);
1224
1225        mutex_lock(&video->device_list_lock);
1226        list_add_tail(&data->entry, &video->video_device_list);
1227        mutex_unlock(&video->device_list_lock);
1228
1229        return status;
1230}
1231
1232/*
1233 *  Arg:
1234 *      video   : video bus device
1235 *
1236 *  Return:
1237 *      none
1238 *
1239 *  Enumerate the video device list of the video bus,
1240 *  bind the ids with the corresponding video devices
1241 *  under the video bus.
1242 */
1243
1244static void acpi_video_device_rebind(struct acpi_video_bus *video)
1245{
1246        struct acpi_video_device *dev;
1247
1248        mutex_lock(&video->device_list_lock);
1249
1250        list_for_each_entry(dev, &video->video_device_list, entry)
1251                acpi_video_device_bind(video, dev);
1252
1253        mutex_unlock(&video->device_list_lock);
1254}
1255
1256/*
1257 *  Arg:
1258 *      video   : video bus device
1259 *      device  : video output device under the video
1260 *              bus
1261 *
1262 *  Return:
1263 *      none
1264 *
1265 *  Bind the ids with the corresponding video devices
1266 *  under the video bus.
1267 */
1268
1269static void
1270acpi_video_device_bind(struct acpi_video_bus *video,
1271                       struct acpi_video_device *device)
1272{
1273        struct acpi_video_enumerated_device *ids;
1274        int i;
1275
1276        for (i = 0; i < video->attached_count; i++) {
1277                ids = &video->attached_array[i];
1278                if (device->device_id == (ids->value.int_val & 0xffff)) {
1279                        ids->bind_info = device;
1280                        acpi_handle_debug(video->device->handle, "%s: %d\n",
1281                                          __func__, i);
1282                }
1283        }
1284}
1285
1286static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1287{
1288        struct acpi_video_bus *video = device->video;
1289        int i;
1290
1291        /*
1292         * If we have a broken _DOD or we have more than 8 output devices
1293         * under the graphics controller node that we can't proper deal with
1294         * in the operation region code currently, no need to test.
1295         */
1296        if (!video->attached_count || video->child_count > 8)
1297                return true;
1298
1299        for (i = 0; i < video->attached_count; i++) {
1300                if ((video->attached_array[i].value.int_val & 0xfff) ==
1301                    (device->device_id & 0xfff))
1302                        return true;
1303        }
1304
1305        return false;
1306}
1307
1308/*
1309 *  Arg:
1310 *      video   : video bus device
1311 *
1312 *  Return:
1313 *      < 0     : error
1314 *
1315 *  Call _DOD to enumerate all devices attached to display adapter
1316 *
1317 */
1318
1319static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1320{
1321        int status;
1322        int count;
1323        int i;
1324        struct acpi_video_enumerated_device *active_list;
1325        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1326        union acpi_object *dod = NULL;
1327        union acpi_object *obj;
1328
1329        if (!video->cap._DOD)
1330                return AE_NOT_EXIST;
1331
1332        status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1333        if (ACPI_FAILURE(status)) {
1334                acpi_handle_info(video->device->handle,
1335                                 "_DOD evaluation failed: %s\n",
1336                                 acpi_format_exception(status));
1337                return status;
1338        }
1339
1340        dod = buffer.pointer;
1341        if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1342                acpi_handle_info(video->device->handle, "Invalid _DOD data\n");
1343                status = -EFAULT;
1344                goto out;
1345        }
1346
1347        acpi_handle_debug(video->device->handle, "Found %d video heads in _DOD\n",
1348                          dod->package.count);
1349
1350        active_list = kcalloc(1 + dod->package.count,
1351                              sizeof(struct acpi_video_enumerated_device),
1352                              GFP_KERNEL);
1353        if (!active_list) {
1354                status = -ENOMEM;
1355                goto out;
1356        }
1357
1358        count = 0;
1359        for (i = 0; i < dod->package.count; i++) {
1360                obj = &dod->package.elements[i];
1361
1362                if (obj->type != ACPI_TYPE_INTEGER) {
1363                        acpi_handle_info(video->device->handle,
1364                                         "Invalid _DOD data in element %d\n", i);
1365                        continue;
1366                }
1367
1368                active_list[count].value.int_val = obj->integer.value;
1369                active_list[count].bind_info = NULL;
1370
1371                acpi_handle_debug(video->device->handle,
1372                                  "_DOD element[%d] = %d\n", i,
1373                                  (int)obj->integer.value);
1374
1375                count++;
1376        }
1377
1378        kfree(video->attached_array);
1379
1380        video->attached_array = active_list;
1381        video->attached_count = count;
1382
1383out:
1384        kfree(buffer.pointer);
1385        return status;
1386}
1387
1388static int
1389acpi_video_get_next_level(struct acpi_video_device *device,
1390                          u32 level_current, u32 event)
1391{
1392        int min, max, min_above, max_below, i, l, delta = 255;
1393        max = max_below = 0;
1394        min = min_above = 255;
1395        /* Find closest level to level_current */
1396        for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1397                l = device->brightness->levels[i];
1398                if (abs(l - level_current) < abs(delta)) {
1399                        delta = l - level_current;
1400                        if (!delta)
1401                                break;
1402                }
1403        }
1404        /* Adjust level_current to closest available level */
1405        level_current += delta;
1406        for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1407                l = device->brightness->levels[i];
1408                if (l < min)
1409                        min = l;
1410                if (l > max)
1411                        max = l;
1412                if (l < min_above && l > level_current)
1413                        min_above = l;
1414                if (l > max_below && l < level_current)
1415                        max_below = l;
1416        }
1417
1418        switch (event) {
1419        case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1420                return (level_current < max) ? min_above : min;
1421        case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1422                return (level_current < max) ? min_above : max;
1423        case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1424                return (level_current > min) ? max_below : min;
1425        case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1426        case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1427                return 0;
1428        default:
1429                return level_current;
1430        }
1431}
1432
1433static void
1434acpi_video_switch_brightness(struct work_struct *work)
1435{
1436        struct acpi_video_device *device = container_of(to_delayed_work(work),
1437                             struct acpi_video_device, switch_brightness_work);
1438        unsigned long long level_current, level_next;
1439        int event = device->switch_brightness_event;
1440        int result = -EINVAL;
1441
1442        /* no warning message if acpi_backlight=vendor or a quirk is used */
1443        if (!device->backlight)
1444                return;
1445
1446        if (!device->brightness)
1447                goto out;
1448
1449        result = acpi_video_device_lcd_get_level_current(device,
1450                                                         &level_current,
1451                                                         false);
1452        if (result)
1453                goto out;
1454
1455        level_next = acpi_video_get_next_level(device, level_current, event);
1456
1457        result = acpi_video_device_lcd_set_level(device, level_next);
1458
1459        if (!result)
1460                backlight_force_update(device->backlight,
1461                                       BACKLIGHT_UPDATE_HOTKEY);
1462
1463out:
1464        if (result)
1465                acpi_handle_info(device->dev->handle,
1466                                 "Failed to switch brightness\n");
1467}
1468
1469int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1470                        void **edid)
1471{
1472        struct acpi_video_bus *video;
1473        struct acpi_video_device *video_device;
1474        union acpi_object *buffer = NULL;
1475        acpi_status status;
1476        int i, length;
1477
1478        if (!device || !acpi_driver_data(device))
1479                return -EINVAL;
1480
1481        video = acpi_driver_data(device);
1482
1483        for (i = 0; i < video->attached_count; i++) {
1484                video_device = video->attached_array[i].bind_info;
1485                length = 256;
1486
1487                if (!video_device)
1488                        continue;
1489
1490                if (!video_device->cap._DDC)
1491                        continue;
1492
1493                if (type) {
1494                        switch (type) {
1495                        case ACPI_VIDEO_DISPLAY_CRT:
1496                                if (!video_device->flags.crt)
1497                                        continue;
1498                                break;
1499                        case ACPI_VIDEO_DISPLAY_TV:
1500                                if (!video_device->flags.tvout)
1501                                        continue;
1502                                break;
1503                        case ACPI_VIDEO_DISPLAY_DVI:
1504                                if (!video_device->flags.dvi)
1505                                        continue;
1506                                break;
1507                        case ACPI_VIDEO_DISPLAY_LCD:
1508                                if (!video_device->flags.lcd)
1509                                        continue;
1510                                break;
1511                        }
1512                } else if (video_device->device_id != device_id) {
1513                        continue;
1514                }
1515
1516                status = acpi_video_device_EDID(video_device, &buffer, length);
1517
1518                if (ACPI_FAILURE(status) || !buffer ||
1519                    buffer->type != ACPI_TYPE_BUFFER) {
1520                        length = 128;
1521                        status = acpi_video_device_EDID(video_device, &buffer,
1522                                                        length);
1523                        if (ACPI_FAILURE(status) || !buffer ||
1524                            buffer->type != ACPI_TYPE_BUFFER) {
1525                                continue;
1526                        }
1527                }
1528
1529                *edid = buffer->buffer.pointer;
1530                return length;
1531        }
1532
1533        return -ENODEV;
1534}
1535EXPORT_SYMBOL(acpi_video_get_edid);
1536
1537static int
1538acpi_video_bus_get_devices(struct acpi_video_bus *video,
1539                           struct acpi_device *device)
1540{
1541        int status = 0;
1542        struct acpi_device *dev;
1543
1544        /*
1545         * There are systems where video module known to work fine regardless
1546         * of broken _DOD and ignoring returned value here doesn't cause
1547         * any issues later.
1548         */
1549        acpi_video_device_enumerate(video);
1550
1551        list_for_each_entry(dev, &device->children, node) {
1552
1553                status = acpi_video_bus_get_one_device(dev, video);
1554                if (status) {
1555                        dev_err(&dev->dev, "Can't attach device\n");
1556                        break;
1557                }
1558                video->child_count++;
1559        }
1560        return status;
1561}
1562
1563/* acpi_video interface */
1564
1565/*
1566 * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1567 * perform any automatic brightness change on receiving a notification.
1568 */
1569static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1570{
1571        return acpi_video_bus_DOS(video, 0,
1572                                  acpi_osi_is_win8() ? 1 : 0);
1573}
1574
1575static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1576{
1577        return acpi_video_bus_DOS(video, 0,
1578                                  acpi_osi_is_win8() ? 0 : 1);
1579}
1580
1581static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1582{
1583        struct acpi_video_bus *video = acpi_driver_data(device);
1584        struct input_dev *input;
1585        int keycode = 0;
1586
1587        if (!video || !video->input)
1588                return;
1589
1590        input = video->input;
1591
1592        switch (event) {
1593        case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
1594                                         * most likely via hotkey. */
1595                keycode = KEY_SWITCHVIDEOMODE;
1596                break;
1597
1598        case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
1599                                         * connector. */
1600                acpi_video_device_enumerate(video);
1601                acpi_video_device_rebind(video);
1602                keycode = KEY_SWITCHVIDEOMODE;
1603                break;
1604
1605        case ACPI_VIDEO_NOTIFY_CYCLE:   /* Cycle Display output hotkey pressed. */
1606                keycode = KEY_SWITCHVIDEOMODE;
1607                break;
1608        case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:     /* Next Display output hotkey pressed. */
1609                keycode = KEY_VIDEO_NEXT;
1610                break;
1611        case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:     /* previous Display output hotkey pressed. */
1612                keycode = KEY_VIDEO_PREV;
1613                break;
1614
1615        default:
1616                acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
1617                                  event);
1618                break;
1619        }
1620
1621        if (acpi_notifier_call_chain(device, event, 0))
1622                /* Something vetoed the keypress. */
1623                keycode = 0;
1624
1625        if (keycode && (report_key_events & REPORT_OUTPUT_KEY_EVENTS)) {
1626                input_report_key(input, keycode, 1);
1627                input_sync(input);
1628                input_report_key(input, keycode, 0);
1629                input_sync(input);
1630        }
1631
1632        return;
1633}
1634
1635static void brightness_switch_event(struct acpi_video_device *video_device,
1636                                    u32 event)
1637{
1638        if (!brightness_switch_enabled)
1639                return;
1640
1641        video_device->switch_brightness_event = event;
1642        schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1643}
1644
1645static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1646{
1647        struct acpi_video_device *video_device = data;
1648        struct acpi_device *device = NULL;
1649        struct acpi_video_bus *bus;
1650        struct input_dev *input;
1651        int keycode = 0;
1652
1653        if (!video_device)
1654                return;
1655
1656        device = video_device->dev;
1657        bus = video_device->video;
1658        input = bus->input;
1659
1660        if (hw_changes_brightness > 0) {
1661                if (video_device->backlight)
1662                        backlight_force_update(video_device->backlight,
1663                                               BACKLIGHT_UPDATE_HOTKEY);
1664                acpi_notifier_call_chain(device, event, 0);
1665                return;
1666        }
1667
1668        switch (event) {
1669        case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:        /* Cycle brightness */
1670                brightness_switch_event(video_device, event);
1671                keycode = KEY_BRIGHTNESS_CYCLE;
1672                break;
1673        case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:  /* Increase brightness */
1674                brightness_switch_event(video_device, event);
1675                keycode = KEY_BRIGHTNESSUP;
1676                break;
1677        case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:  /* Decrease brightness */
1678                brightness_switch_event(video_device, event);
1679                keycode = KEY_BRIGHTNESSDOWN;
1680                break;
1681        case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1682                brightness_switch_event(video_device, event);
1683                keycode = KEY_BRIGHTNESS_ZERO;
1684                break;
1685        case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:     /* display device off */
1686                brightness_switch_event(video_device, event);
1687                keycode = KEY_DISPLAY_OFF;
1688                break;
1689        default:
1690                acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event);
1691                break;
1692        }
1693
1694        acpi_notifier_call_chain(device, event, 0);
1695
1696        if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
1697                input_report_key(input, keycode, 1);
1698                input_sync(input);
1699                input_report_key(input, keycode, 0);
1700                input_sync(input);
1701        }
1702
1703        return;
1704}
1705
1706static int acpi_video_resume(struct notifier_block *nb,
1707                                unsigned long val, void *ign)
1708{
1709        struct acpi_video_bus *video;
1710        struct acpi_video_device *video_device;
1711        int i;
1712
1713        switch (val) {
1714        case PM_HIBERNATION_PREPARE:
1715        case PM_SUSPEND_PREPARE:
1716        case PM_RESTORE_PREPARE:
1717                return NOTIFY_DONE;
1718        }
1719
1720        video = container_of(nb, struct acpi_video_bus, pm_nb);
1721
1722        dev_info(&video->device->dev, "Restoring backlight state\n");
1723
1724        for (i = 0; i < video->attached_count; i++) {
1725                video_device = video->attached_array[i].bind_info;
1726                if (video_device && video_device->brightness)
1727                        acpi_video_device_lcd_set_level(video_device,
1728                                        video_device->brightness->curr);
1729        }
1730
1731        return NOTIFY_OK;
1732}
1733
1734static acpi_status
1735acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1736                        void **return_value)
1737{
1738        struct acpi_device *device = context;
1739        struct acpi_device *sibling;
1740        int result;
1741
1742        if (handle == device->handle)
1743                return AE_CTRL_TERMINATE;
1744
1745        result = acpi_bus_get_device(handle, &sibling);
1746        if (result)
1747                return AE_OK;
1748
1749        if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1750                        return AE_ALREADY_EXISTS;
1751
1752        return AE_OK;
1753}
1754
1755static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1756{
1757        struct backlight_properties props;
1758        struct pci_dev *pdev;
1759        acpi_handle acpi_parent;
1760        struct device *parent = NULL;
1761        int result;
1762        static int count;
1763        char *name;
1764
1765        result = acpi_video_init_brightness(device);
1766        if (result)
1767                return;
1768
1769        if (disable_backlight_sysfs_if > 0)
1770                return;
1771
1772        name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1773        if (!name)
1774                return;
1775        count++;
1776
1777        acpi_get_parent(device->dev->handle, &acpi_parent);
1778
1779        pdev = acpi_get_pci_dev(acpi_parent);
1780        if (pdev) {
1781                parent = &pdev->dev;
1782                pci_dev_put(pdev);
1783        }
1784
1785        memset(&props, 0, sizeof(struct backlight_properties));
1786        props.type = BACKLIGHT_FIRMWARE;
1787        props.max_brightness =
1788                device->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
1789        device->backlight = backlight_device_register(name,
1790                                                      parent,
1791                                                      device,
1792                                                      &acpi_backlight_ops,
1793                                                      &props);
1794        kfree(name);
1795        if (IS_ERR(device->backlight)) {
1796                device->backlight = NULL;
1797                return;
1798        }
1799
1800        /*
1801         * Save current brightness level in case we have to restore it
1802         * before acpi_video_device_lcd_set_level() is called next time.
1803         */
1804        device->backlight->props.brightness =
1805                        acpi_video_get_brightness(device->backlight);
1806
1807        device->cooling_dev = thermal_cooling_device_register("LCD",
1808                                device->dev, &video_cooling_ops);
1809        if (IS_ERR(device->cooling_dev)) {
1810                /*
1811                 * Set cooling_dev to NULL so we don't crash trying to free it.
1812                 * Also, why the hell we are returning early and not attempt to
1813                 * register video output if cooling device registration failed?
1814                 * -- dtor
1815                 */
1816                device->cooling_dev = NULL;
1817                return;
1818        }
1819
1820        dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1821                 device->cooling_dev->id);
1822        result = sysfs_create_link(&device->dev->dev.kobj,
1823                        &device->cooling_dev->device.kobj,
1824                        "thermal_cooling");
1825        if (result)
1826                pr_info("sysfs link creation failed\n");
1827
1828        result = sysfs_create_link(&device->cooling_dev->device.kobj,
1829                        &device->dev->dev.kobj, "device");
1830        if (result)
1831                pr_info("Reverse sysfs link creation failed\n");
1832}
1833
1834static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1835{
1836        struct acpi_video_device *dev;
1837        union acpi_object *levels;
1838
1839        mutex_lock(&video->device_list_lock);
1840        list_for_each_entry(dev, &video->video_device_list, entry) {
1841                if (!acpi_video_device_lcd_query_levels(dev->dev->handle, &levels))
1842                        kfree(levels);
1843        }
1844        mutex_unlock(&video->device_list_lock);
1845}
1846
1847static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
1848{
1849        /*
1850         * Do not create backlight device for video output
1851         * device that is not in the enumerated list.
1852         */
1853        if (!acpi_video_device_in_dod(dev)) {
1854                dev_dbg(&dev->dev->dev, "not in _DOD list, ignore\n");
1855                return false;
1856        }
1857
1858        if (only_lcd)
1859                return dev->flags.lcd;
1860        return true;
1861}
1862
1863static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1864{
1865        struct acpi_video_device *dev;
1866
1867        if (video->backlight_registered)
1868                return 0;
1869
1870        acpi_video_run_bcl_for_osi(video);
1871
1872        if (acpi_video_get_backlight_type() != acpi_backlight_video)
1873                return 0;
1874
1875        mutex_lock(&video->device_list_lock);
1876        list_for_each_entry(dev, &video->video_device_list, entry) {
1877                if (acpi_video_should_register_backlight(dev))
1878                        acpi_video_dev_register_backlight(dev);
1879        }
1880        mutex_unlock(&video->device_list_lock);
1881
1882        video->backlight_registered = true;
1883
1884        video->pm_nb.notifier_call = acpi_video_resume;
1885        video->pm_nb.priority = 0;
1886        return register_pm_notifier(&video->pm_nb);
1887}
1888
1889static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1890{
1891        if (device->backlight) {
1892                backlight_device_unregister(device->backlight);
1893                device->backlight = NULL;
1894        }
1895        if (device->brightness) {
1896                kfree(device->brightness->levels);
1897                kfree(device->brightness);
1898                device->brightness = NULL;
1899        }
1900        if (device->cooling_dev) {
1901                sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1902                sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1903                thermal_cooling_device_unregister(device->cooling_dev);
1904                device->cooling_dev = NULL;
1905        }
1906}
1907
1908static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1909{
1910        struct acpi_video_device *dev;
1911        int error;
1912
1913        if (!video->backlight_registered)
1914                return 0;
1915
1916        error = unregister_pm_notifier(&video->pm_nb);
1917
1918        mutex_lock(&video->device_list_lock);
1919        list_for_each_entry(dev, &video->video_device_list, entry)
1920                acpi_video_dev_unregister_backlight(dev);
1921        mutex_unlock(&video->device_list_lock);
1922
1923        video->backlight_registered = false;
1924
1925        return error;
1926}
1927
1928static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1929{
1930        acpi_status status;
1931        struct acpi_device *adev = device->dev;
1932
1933        status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1934                                             acpi_video_device_notify, device);
1935        if (ACPI_FAILURE(status))
1936                dev_err(&adev->dev, "Error installing notify handler\n");
1937        else
1938                device->flags.notify = 1;
1939}
1940
1941static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1942{
1943        struct input_dev *input;
1944        struct acpi_video_device *dev;
1945        int error;
1946
1947        video->input = input = input_allocate_device();
1948        if (!input) {
1949                error = -ENOMEM;
1950                goto out;
1951        }
1952
1953        error = acpi_video_bus_start_devices(video);
1954        if (error)
1955                goto err_free_input;
1956
1957        snprintf(video->phys, sizeof(video->phys),
1958                        "%s/video/input0", acpi_device_hid(video->device));
1959
1960        input->name = acpi_device_name(video->device);
1961        input->phys = video->phys;
1962        input->id.bustype = BUS_HOST;
1963        input->id.product = 0x06;
1964        input->dev.parent = &video->device->dev;
1965        input->evbit[0] = BIT(EV_KEY);
1966        set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1967        set_bit(KEY_VIDEO_NEXT, input->keybit);
1968        set_bit(KEY_VIDEO_PREV, input->keybit);
1969        set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1970        set_bit(KEY_BRIGHTNESSUP, input->keybit);
1971        set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1972        set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1973        set_bit(KEY_DISPLAY_OFF, input->keybit);
1974
1975        error = input_register_device(input);
1976        if (error)
1977                goto err_stop_dev;
1978
1979        mutex_lock(&video->device_list_lock);
1980        list_for_each_entry(dev, &video->video_device_list, entry)
1981                acpi_video_dev_add_notify_handler(dev);
1982        mutex_unlock(&video->device_list_lock);
1983
1984        return 0;
1985
1986err_stop_dev:
1987        acpi_video_bus_stop_devices(video);
1988err_free_input:
1989        input_free_device(input);
1990        video->input = NULL;
1991out:
1992        return error;
1993}
1994
1995static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1996{
1997        if (dev->flags.notify) {
1998                acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1999                                           acpi_video_device_notify);
2000                dev->flags.notify = 0;
2001        }
2002}
2003
2004static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
2005{
2006        struct acpi_video_device *dev;
2007
2008        mutex_lock(&video->device_list_lock);
2009        list_for_each_entry(dev, &video->video_device_list, entry)
2010                acpi_video_dev_remove_notify_handler(dev);
2011        mutex_unlock(&video->device_list_lock);
2012
2013        acpi_video_bus_stop_devices(video);
2014        input_unregister_device(video->input);
2015        video->input = NULL;
2016}
2017
2018static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
2019{
2020        struct acpi_video_device *dev, *next;
2021
2022        mutex_lock(&video->device_list_lock);
2023        list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
2024                list_del(&dev->entry);
2025                kfree(dev);
2026        }
2027        mutex_unlock(&video->device_list_lock);
2028
2029        return 0;
2030}
2031
2032static int instance;
2033
2034static int acpi_video_bus_add(struct acpi_device *device)
2035{
2036        struct acpi_video_bus *video;
2037        int error;
2038        acpi_status status;
2039
2040        status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
2041                                device->parent->handle, 1,
2042                                acpi_video_bus_match, NULL,
2043                                device, NULL);
2044        if (status == AE_ALREADY_EXISTS) {
2045                pr_info(FW_BUG
2046                        "Duplicate ACPI video bus devices for the"
2047                        " same VGA controller, please try module "
2048                        "parameter \"video.allow_duplicates=1\""
2049                        "if the current driver doesn't work.\n");
2050                if (!allow_duplicates)
2051                        return -ENODEV;
2052        }
2053
2054        video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
2055        if (!video)
2056                return -ENOMEM;
2057
2058        /* a hack to fix the duplicate name "VID" problem on T61 */
2059        if (!strcmp(device->pnp.bus_id, "VID")) {
2060                if (instance)
2061                        device->pnp.bus_id[3] = '0' + instance;
2062                instance++;
2063        }
2064        /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
2065        if (!strcmp(device->pnp.bus_id, "VGA")) {
2066                if (instance)
2067                        device->pnp.bus_id[3] = '0' + instance;
2068                instance++;
2069        }
2070
2071        video->device = device;
2072        strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
2073        strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
2074        device->driver_data = video;
2075
2076        acpi_video_bus_find_cap(video);
2077        error = acpi_video_bus_check(video);
2078        if (error)
2079                goto err_free_video;
2080
2081        mutex_init(&video->device_list_lock);
2082        INIT_LIST_HEAD(&video->video_device_list);
2083
2084        error = acpi_video_bus_get_devices(video, device);
2085        if (error)
2086                goto err_put_video;
2087
2088        pr_info("%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
2089               ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
2090               video->flags.multihead ? "yes" : "no",
2091               video->flags.rom ? "yes" : "no",
2092               video->flags.post ? "yes" : "no");
2093        mutex_lock(&video_list_lock);
2094        list_add_tail(&video->entry, &video_bus_head);
2095        mutex_unlock(&video_list_lock);
2096
2097        acpi_video_bus_register_backlight(video);
2098        acpi_video_bus_add_notify_handler(video);
2099
2100        return 0;
2101
2102err_put_video:
2103        acpi_video_bus_put_devices(video);
2104        kfree(video->attached_array);
2105err_free_video:
2106        kfree(video);
2107        device->driver_data = NULL;
2108
2109        return error;
2110}
2111
2112static int acpi_video_bus_remove(struct acpi_device *device)
2113{
2114        struct acpi_video_bus *video = NULL;
2115
2116
2117        if (!device || !acpi_driver_data(device))
2118                return -EINVAL;
2119
2120        video = acpi_driver_data(device);
2121
2122        acpi_video_bus_remove_notify_handler(video);
2123        acpi_video_bus_unregister_backlight(video);
2124        acpi_video_bus_put_devices(video);
2125
2126        mutex_lock(&video_list_lock);
2127        list_del(&video->entry);
2128        mutex_unlock(&video_list_lock);
2129
2130        kfree(video->attached_array);
2131        kfree(video);
2132
2133        return 0;
2134}
2135
2136static int __init is_i740(struct pci_dev *dev)
2137{
2138        if (dev->device == 0x00D1)
2139                return 1;
2140        if (dev->device == 0x7000)
2141                return 1;
2142        return 0;
2143}
2144
2145static int __init intel_opregion_present(void)
2146{
2147        int opregion = 0;
2148        struct pci_dev *dev = NULL;
2149        u32 address;
2150
2151        for_each_pci_dev(dev) {
2152                if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2153                        continue;
2154                if (dev->vendor != PCI_VENDOR_ID_INTEL)
2155                        continue;
2156                /* We don't want to poke around undefined i740 registers */
2157                if (is_i740(dev))
2158                        continue;
2159                pci_read_config_dword(dev, 0xfc, &address);
2160                if (!address)
2161                        continue;
2162                opregion = 1;
2163        }
2164        return opregion;
2165}
2166
2167/* Check if the chassis-type indicates there is no builtin LCD panel */
2168static bool dmi_is_desktop(void)
2169{
2170        const char *chassis_type;
2171        unsigned long type;
2172
2173        chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
2174        if (!chassis_type)
2175                return false;
2176
2177        if (kstrtoul(chassis_type, 10, &type) != 0)
2178                return false;
2179
2180        switch (type) {
2181        case 0x03: /* Desktop */
2182        case 0x04: /* Low Profile Desktop */
2183        case 0x05: /* Pizza Box */
2184        case 0x06: /* Mini Tower */
2185        case 0x07: /* Tower */
2186        case 0x10: /* Lunch Box */
2187        case 0x11: /* Main Server Chassis */
2188                return true;
2189        }
2190
2191        return false;
2192}
2193
2194/*
2195 * We're seeing a lot of bogus backlight interfaces on newer machines
2196 * without a LCD such as desktops, servers and HDMI sticks. Checking the
2197 * lcd flag fixes this, enable this by default on any machines which are:
2198 * 1.  Win8 ready (where we also prefer the native backlight driver, so
2199 *     normally the acpi_video code should not register there anyways); *and*
2200 * 2.1 Report a desktop/server DMI chassis-type, or
2201 * 2.2 Are an ACPI-reduced-hardware platform (and thus won't use the EC for
2202       backlight control)
2203 */
2204static bool should_check_lcd_flag(void)
2205{
2206        if (!acpi_osi_is_win8())
2207                return false;
2208
2209        if (dmi_is_desktop())
2210                return true;
2211
2212        if (acpi_reduced_hardware())
2213                return true;
2214
2215        return false;
2216}
2217
2218int acpi_video_register(void)
2219{
2220        int ret = 0;
2221
2222        mutex_lock(&register_count_mutex);
2223        if (register_count) {
2224                /*
2225                 * if the function of acpi_video_register is already called,
2226                 * don't register the acpi_video_bus again and return no error.
2227                 */
2228                goto leave;
2229        }
2230
2231        if (only_lcd == -1)
2232                only_lcd = should_check_lcd_flag();
2233
2234        dmi_check_system(video_dmi_table);
2235
2236        ret = acpi_bus_register_driver(&acpi_video_bus);
2237        if (ret)
2238                goto leave;
2239
2240        /*
2241         * When the acpi_video_bus is loaded successfully, increase
2242         * the counter reference.
2243         */
2244        register_count = 1;
2245
2246leave:
2247        mutex_unlock(&register_count_mutex);
2248        return ret;
2249}
2250EXPORT_SYMBOL(acpi_video_register);
2251
2252void acpi_video_unregister(void)
2253{
2254        mutex_lock(&register_count_mutex);
2255        if (register_count) {
2256                acpi_bus_unregister_driver(&acpi_video_bus);
2257                register_count = 0;
2258        }
2259        mutex_unlock(&register_count_mutex);
2260}
2261EXPORT_SYMBOL(acpi_video_unregister);
2262
2263void acpi_video_unregister_backlight(void)
2264{
2265        struct acpi_video_bus *video;
2266
2267        mutex_lock(&register_count_mutex);
2268        if (register_count) {
2269                mutex_lock(&video_list_lock);
2270                list_for_each_entry(video, &video_bus_head, entry)
2271                        acpi_video_bus_unregister_backlight(video);
2272                mutex_unlock(&video_list_lock);
2273        }
2274        mutex_unlock(&register_count_mutex);
2275}
2276
2277bool acpi_video_handles_brightness_key_presses(void)
2278{
2279        bool have_video_busses;
2280
2281        mutex_lock(&video_list_lock);
2282        have_video_busses = !list_empty(&video_bus_head);
2283        mutex_unlock(&video_list_lock);
2284
2285        return have_video_busses &&
2286               (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS);
2287}
2288EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);
2289
2290/*
2291 * This is kind of nasty. Hardware using Intel chipsets may require
2292 * the video opregion code to be run first in order to initialise
2293 * state before any ACPI video calls are made. To handle this we defer
2294 * registration of the video class until the opregion code has run.
2295 */
2296
2297static int __init acpi_video_init(void)
2298{
2299        /*
2300         * Let the module load even if ACPI is disabled (e.g. due to
2301         * a broken BIOS) so that i915.ko can still be loaded on such
2302         * old systems without an AcpiOpRegion.
2303         *
2304         * acpi_video_register() will report -ENODEV later as well due
2305         * to acpi_disabled when i915.ko tries to register itself afterwards.
2306         */
2307        if (acpi_disabled)
2308                return 0;
2309
2310        if (intel_opregion_present())
2311                return 0;
2312
2313        return acpi_video_register();
2314}
2315
2316static void __exit acpi_video_exit(void)
2317{
2318        acpi_video_detect_exit();
2319        acpi_video_unregister();
2320
2321        return;
2322}
2323
2324module_init(acpi_video_init);
2325module_exit(acpi_video_exit);
2326